U.S. patent number 6,117,507 [Application Number 08/478,358] was granted by the patent office on 2000-09-12 for sealed inversion liner for lining an existing pipeline or conduit.
This patent grant is currently assigned to Insituform (Netherlands) B.V.. Invention is credited to Edward Peter Smith.
United States Patent |
6,117,507 |
Smith |
September 12, 2000 |
Sealed inversion liner for lining an existing pipeline or
conduit
Abstract
A method for lining a passageway which comprises providing a
plurality of tube sections connected end to end, pulling a first
tube section through the passageway in a collapsed condition and
thereafter everting a second tube section into the interior of said
collapsed first tube section to cause it to expand outwardly toward
the interior walls of said passageway.
Inventors: |
Smith; Edward Peter
(Ravensthorpe, GB) |
Assignee: |
Insituform (Netherlands) B.V.
(NL)
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Family
ID: |
27450295 |
Appl.
No.: |
08/478,358 |
Filed: |
June 7, 1995 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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203376 |
Mar 1, 1994 |
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049238 |
Apr 21, 1993 |
5407630 |
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762004 |
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Foreign Application Priority Data
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Mar 21, 1989 [GB] |
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8906467 |
Oct 27, 1989 [GB] |
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8924243 |
Oct 27, 1989 [GB] |
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8924244 |
Jan 3, 1990 [GB] |
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9000058 |
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Current U.S.
Class: |
428/36.9;
428/36.4; 156/295; 428/36.91; 156/287; 138/97; 138/98 |
Current CPC
Class: |
B29C
48/09 (20190201); B29C 63/34 (20130101); F16L
55/1656 (20130101); B29D 23/001 (20130101); B29C
48/022 (20190201); B29C 48/0019 (20190201); B29C
48/0012 (20190201); B29C 48/16 (20190201); B29K
2105/06 (20130101); Y10T 428/1372 (20150115); B29C
48/0018 (20190201); Y10T 428/139 (20150115); B29C
48/10 (20190201); B29C 48/21 (20190201); B29C
48/0021 (20190201); B29C 48/08 (20190201); B29L
2023/006 (20130101); B29C 48/12 (20190201); Y10T
428/1393 (20150115); B29C 48/13 (20190201); B29C
65/62 (20130101) |
Current International
Class: |
B29D
23/00 (20060101); F16L 55/162 (20060101); B29C
47/00 (20060101); B29C 63/34 (20060101); F16L
55/165 (20060101); B29C 65/62 (20060101); B29C
65/56 (20060101); B29D 023/00 () |
Field of
Search: |
;428/36.4,36.9,36.91
;264/36,516,269 ;156/287,295 ;138/97.98 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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275060 |
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Jul 1988 |
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EP |
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1449455 |
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Sep 1976 |
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GB |
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Primary Examiner: Dees; Jose G.
Assistant Examiner: Williamson; Michael A.
Attorney, Agent or Firm: Cowan, Liebowitz & Latman, P.C.
Wolfson; Michael I. Buchanan; Lloyd G.
Parent Case Text
This is a continuation of application Ser. No. 08/203,376 filed
Mar. 1, 1994 now abandoned which is a divisional application of
Ser. No. 08/049,238, filed Apr. 21, 1993, now U.S. Pat. No.
5,407,630, which is a continuation of Ser. No. 07/762,004, filed
Sep. 19, 1991, now abandoned, which is a 371 of PCT/GB90/00412
filed Mar. 19, 1990.
Claims
I claim:
1. A flexible tubular liner assembly having at least one section of
a resin absorbent layer impregnated with a curable resin for lining
an existing conduit of a known length, comprising:
a lining tube section having a leading end and a trailing end, the
tube formed from at least an impermeable membrane and having a
sealed leading end to prevent ingress of air to the interior
thereof;
an inflation tube section having a leading end and a trailing end,
the inflation tube formed from at least an impermeable membrane
with the leading end sealed to the trailing end of the lining tube
section and the trailing end of the inflation tube sealed to
prevent ingress of air into the interior thereby forming a
continuous tube substantially free of air;
at least one of the lining tube section and the inflation tube
section having a layer of resin absorbent material with the
impermeable membrane bonded to the layer of resin absorbent layer;
and
each of the lining tube section and the inflation tube section of a
length at least equal to the length of the conduit to be lined with
a curable resin impregnated into the resin absorbent layer.
2. The flexible tubular liner of claim 1, further including an
impermeable flexible tubular connection section secured to the
trailing end of the lining tube section and the leading end of the
inflation tube section and sealed to said sections to prevent
ingress of air into the interior of said tubular sections.
3. The flexible tubular liner of claim 2, wherein the connection
section has a length sufficient to permit eversion of the inflation
tube section into the lining tube section from a predetermined
distance remote from the conduit to be lined.
4. The flexible tubular liner of claim 1, wherein the lining
section has the layer of resin absorbent material disposed on the
interior of the impermeable layer.
5. The flexible tubular liner of claim 1, wherein the inflation
tube section has a layer of resin absorbent material with the
impermeable layer bonded to the outer surface thereof.
6. The flexible tubular liner of claim 1, wherein both the lining
tube section and the inflation tube section includes a layer of
resin absorbent material with the impermeable layer bonded to the
outer surface thereof.
7. The flexible tubular liner of claim 1, further including a
flexible tubular preliner section comprising a fluid permeable
membrane attached to the sealed leading end of the lining tube
section.
8. A flexible tubular liner having at least one section of a resin
absorbent layer impregnated with a curable resin for lining an
existing conduit of a known length, comprising:
a flexible fluid impermeable tubular preliner section having a
leading end and a trailing end;
a lining tube section having a leading end and a trailing end, the
tube formed from at least an impermeable membrane and having a
sealed leading end to prevent ingress of air into the interior
thereof and attached to the trailing end of the preliner
section;
a flexible tubular connection section comprising a fluid
impermeable membrane secured to the trailing end of the tubular
lining section and sealed to prevent ingress of air into the
interior of the tubular sections;
a flexible inflation tube section having a leading end and a
trailing end, the inflation tube section formed from at least an
impermeable membrane with the leading end sealed to the trailing
end of the connection section to prevent ingress of air into the
tubular sections and the trailing end of the inflation tube sealed
to prevent ingress of air into the interior thereby forming a
continuous tube substantially free of air;
at least one of the lining tube section and the inflation tube
section having a layer of resin absorbent material with the
impermeable membrane bonded to the outer surface of the layer of
absorbent material;
each of the preliner section, lining tube section and inflation
tube section of at least a length equal to the length of the
conduit to be lined and the resin absorbent layer impregnated with
a curable resin.
9. The flexible tubular liner of claim 8, wherein the length of
each of said preliner tube, lining tube and inflation tube sections
are substantially the length of said conduit to be lined.
10. The flexible tubular liner of claim 8, wherein the connection
section has a length sufficient to permit eversion of the inflation
tube section into the lining tube section from a predetermined
distance remote from the conduit.
11. The flexible tubular liner of claim 8, wherein the lining tube
section has a layer of resin absorbent material with the
impermeable membrane bonded to the outer surface thereof.
12. The flexible tubular liner of claim 8, wherein the inflation
tube section has a layer of resin absorbent material with the
impermeable membrane bonded to the outer surface thereof.
13. The flexible tubular liner of claim 8, wherein both the lining
tube section and the inflation tube section have a layer of resin
absorbent material with the impermeable membrane bonded to an outer
surface thereof.
14. A flexible tubular liner assembly having at least one section
including a resin absorbent layer for lining an existing conduit of
a known length, comprising:
a lining tube section having a leading end and a trailing end, the
tube formed from at least an impermeable membrane and having a
sealed leading end to prevent ingress of air to the interior
thereof;
an inflation tube section having a leading end and a trailing end,
the inflation tube formed from at least an impermeable membrane
with the leading end sealed to the trailing end of the lining tube
section and the trailing end of the inflation tube sealed to
prevent ingress of air into the interior thereby forming a
continuous air tight tube;
at least one of the lining tube section and the inflation tube
section having a layer of resin absorbent material with the
impermeable membrane bonded to the later of resin absorbent layer;
and
each of the lining tube section and the inflation tube section of a
length at least equal to the length of the conduit to be lined.
15. The flexible tubular liner of claim 14, further including a
flexible tubular connection section secured to the trailing end of
the tubular lining section and the leading end of the inflation
tube and sealed to said sections to prevent ingress of air into the
interior of said tubular sections.
16. The flexible tubular liner of claim 15, wherein the connection
section has a length sufficient to permit eversion of the inflation
section into the lining section from a predetermined distance
remote from the conduit to be lined.
17. The flexible tubular liner of claim 14, wherein the lining
section including a layer of resin absorbent material disposed on
the interior of the impermeable layer.
18. The flexible tubular liner of claim 14, wherein the inflation
section includes a layer of resin absorbent material disposed on
the interior of the impermeable layer.
19. The flexible tubular liner of claim 14, wherein both the lining
section and the inflation section have a layer of resin absorbent
material disposed on the interior of the impermeable layer.
20. The flexible tubular liner of claim 14, further including a
flexible tubular preliner section of a fluid impermeable material
attached to the sealed leading end of the lining section.
21. The flexible tubular liner of claim 14, further including a
cureable resin impregnated into the resin absorbent layer.
22. The flexible tubular liner of claim 19, further including a
cureable resin impregnated into both resin absorbent layers.
23. A flexible tubular liner having at least one section of a resin
absorbent layer for lining an existing conduit of a known length,
comprising:
a flexible fluid impermeable tubular preliner section having a
leading end and a trailing end;
a lining tube section having a leading end and a trailing end, the
tube formed from at least an impermeable membrane and having a
sealed leading end to prevent ingress of air to the interior
thereof and attached to the trailing end of the preliner
section;
a flexible tubular connection section comprising a fluid
impermeable membrane secured to the trailing end of the tubular
lining section and sealed to prevent ingress of air into the
interior of the tubular sections;
a flexible inflation tube section having a leading end and a
trailing end, the inflation tube section formed from at least an
impermeable membrane with the leading end sealed to the trailing
end of the connection section to prevent ingress of air into the
tubular sections and the trailing end of the inflation tube sealed
to prevent ingress of air into the interior thereby forming a
continuous air tight tube;
at least one of the lining tube section and the inflation tube
section having a layer of resin absorbent material with the
impermeable membrane bonded to the outer surface thin membrane the
impermeable layer; and
each of the preliner section, lining tube section and inflation
tube section of at least a length equal to the length of the
conduit to be lined.
24. The flexible tubular liner of claim 23, wherein the connection
section has a length sufficient to permit eversion of the inflation
section into the lining section from a predetermined distance
remote from the conduit.
25. The flexible tubular liner of claim 23, wherein the lining
section includes a layer of resin absorbent material disposed on
the interior of the unpermeable layer.
26. The flexible tubular liner of claim 23, wherein the inflation
section includes a layer of resin absorbent material disposed on
the interior of the unpermeable layer.
27. The flexible tubular liner of claim 23, wherein both the lining
section and the inflation section includes a layer of resin
absorbent material disposed on the unpermeable layer.
28. The flexible tubular liner of claim 23, further including a
cureable resin impregnated into the resin absorbent layer.
29. The flexible tubular liner of claim 27, further including a
cureable resin impregnated into both resin absorbent layers.
Description
This invention relates to the lining of pipelines or passageways by
a process which has become known as "soft lining".
BACKGROUND
A soft lining process involves utilising a flexible tube which is
sized to the diameter and length of the pipeline or passageway to
be lined. The tube is coated or impregnated with a curable
synthetic resin which cures after the lining tube has been placed
in position lining the surface of the pipeline or passageway in
order either to form an adhesive which anchors the lining tube to
the pipeline or passageway surface or to form in effect a moulded
body defining a rigid pipe which is free standing inside the
pipeline or passageway. The lining tube is inserted in the pipeline
or passageway whilst the resin is still soft, and is shaped to the
passageway surface by fluid pressure, and whilst it is held in this
condition the resin is cured usually by the application of heat or
more recently by the application of light radiation supplied for
example by ultraviolet lights. In the latter case, the resin system
chosen has to be activatable by the radiation.
The most widely practised method of soft lining is disclosed in
British Patent No. 1449455 and in such method the lining tube is
everted into the pipeline or passageway from one end thereof, the
lining tube being provided on its outer side with an impermeable
coating or film which after eversion becomes the inner surface of
the pipelining providing a smooth flow enhancing surface to the
interior of the re-lined pipeline or passageway.
SUMMARY OF THE INVENTION
In accordance with the present invention there is provided a soft
lining method wherein a lining tube is constructed in two sections
each at least approximately equal to the length of the pipeline or
passageway to be lined, the sections being connected end to end,
and the insertion process comprises either pulling in of one of the
sections followed by eversion of the other section into the first
mentioned section, or eversion of one section which causes pulling
in of the other section.
In the preferred arrangement, the lining tube is in fact made up of
three sections each of a length equal to the length of the section
of the pipeline or passageway to be lined or greater than such
length, said three sections comprising a first section referred to
herein as a preliner tube, a second section being a lining tube and
comprising a tube of a material which is or is adapted to be
impregnated or coated with curable synthetic resin, and a third
section referred to herein as the inflation tube, the purpose of
which is to inflate the lining tube when it is in position by
eversion of the inflation tube into the lining tube.
The inflation tube may also be of or include a material which is
coated or impregnated with curable synthetic resin, but as it is
everted, it will preferably in such case have an outer membrane for
containing the resin. For example, the inflation tube may typically
be constructed and impregnated as described in British Patent No.
1449455.
In the instant invention, the lining method can comprise only the
utilisation of the preliner tube and the lining tube, the prelining
tube typically comprising a strong fabric coated tube of sufficient
tensile strength and flexibility, which may be everted into the
pipeline or passageway by conventional everting techniques using a
liquid typically water as the eversion medium.
As the prelining tube is being inserted, the lining tube which is
connected to the tail end of the prelining tube is pulled into the
pipeline or passageway and it will be buoyantly supported in the
everting water as it is so being pulled in when in reaches the
desired position, it may be inflated by any suitable means, for
example by a separate inflation tube. The lining tube in this
embodiment may be sealed at both ends after being filled with resin
to impregnate resin absorbent layers of the tube, and also after
removal of the air from inside the tube. The removal of air and the
sealing of ends is particularly advantageous insofar as if there
are bubbles of air in the resin, these tend to cause imperfections
in the finished, cured lining which can lead to permeation and
mechanical difficulties.
When the lining tube is in position, the trailing end must be
opened to allow insertion of the inflating medium and/or inflation
tube but the ingress of air into the impregnated lining tube can
easily be avoided.
The second inventive aspect comprises the utilisation of the lining
tube to the trailing end of which is connected the inflation tube.
The leading end of the lining tube and the trailing end of the
inflation tube may be
sealed, and where the two tubes are connected they may also be
sealed to each other to make a continuous tube. This ensures that
all air can be excluded from the inside of the assembly comprising
the two tubes so that resin contained therein will thoroughly
impregnate the absorbent layers of the lining tube and/or of the
inflation tube. The inflation tube and lining tube may be
interconnected by a section referred to as the connection tube
permitting the inflation tube to be everted at the appropriate
stage of the insertion. To this end the connection tube may be
provided with a tuck or fold so that it is folded in upon itself
which will facilitate the operation of the inversion process, as
will be explained in more particular detail with reference to the
embodiment of the invention which is described hereinafter.
Obviously the best results flow from the combined effects of the
two inventive aspects i.e. when the assembly comprises first,
second and third tubes and the lining sequence comprises everting
the prelining tube into the pipeline or passageway for the
placement of the lining tube in the pipeline or passageway followed
by the eversion of the inflation tube into the lining tube to
inflate same onto the prelining tube and supported against the
passageway surface and held in such condition until the resin of
the lining tube and/or the inflation tube is cured.
The utilisation of a prelining tube has the desired advantage that
the prelining tube prevents the ingress of resin into lateral
connections which meet the pipeline or passageway being lined.
THE DRAWINGS
One embodiment of the invention will now be described, by way of
example, with reference to the accompanying diagrammatic drawings,
wherein:
FIG. 1 is a perspective view of a tubular assembly for insertion
into a pipeline or passageway in accordance with one embodiment of
the present invention;
FIGS. 1A, 1B and 1C respectively show in enlarged detail the
respective sections of the tube assembly shown in FIG. 1, and in
cross section;
FIG. 2 shows a connecting section of the assembly shown in FIG.
1;
FIGS. 3-7 show respective stages in the installation of the tube
assembly of FIG. 1 in an underground sewer;
FIG. 8 shows in enlarged detail a section of the lining tube when
in the sewer and lining same; and
FIG. 9 is a sectional elevation to an enlarged scale illustrating
one side of the installed lining.
Referring to the drawings, a flexible tubular liner assembly is
illustrated by reference 10 in FIG. 1. The assembly is shown as
being made up of three sections namely a first section or preliner
tube 12, a second section or lining tube 14 and a third section or
inflation tube 16, these being connected end to end for example at
joint regions 18 and 20. Each of the sections 12, 14 and 16 as
shown is of a length at least equal to a length L, which is the
length of the pipeline or passageway to be lined by the
assembly.
The joint 18 is formed in that the sealed end of lining tube 14 is
tied to the sealed trailing end of preliner tube 12, but the
junction between lining tube 14 and inflation tube 16 indicated by
reference 20 is constituted by a connection section 22 which is
referred to herein for convenience as an inversion tube, whose
function will be explained in more detail hereinafter.
PREFERRED EMBODIMENT
As shown in FIG. 1A the prelining tube 12 is a single layer tube
which may be made up of a woven fabric 24 which is covered with a
plastic or rubberised coating so as to give the tube 12 the
required strength. The requirements of the tube 12 are that it
should be of sufficient strength to perform its function and also
should be impermeable to a fluid, especially water, which is used
to evert this tube 12 into the pipeline or passageway to be
lined.
The tube 14 on the other hand as shown in FIG. 1B comprises an
outer coating 26 of an impermeable film material such as
polyurethane or a laminated material. The coating 26 is bonded to a
relatively thick felt layer 28, and in order to form the tubular
structure as shown in FIG. 1B, this material is coiled into tubular
form and abutting seam 30 has stitching 34 bridging same in order
to connect the butting ends. The stitching is covered by a sealing
strip 36.
Inside the layer 28 is a further felt layer 36 which is formed into
a tube so that the edges overlap, and through the overlapped edges
there is stitching in order to form the tubular structure. As many
layers 36 as are required may be embodied in the tube 14. The
layers 28 and 36 are of a material i.e. needled felt which has an
excellent resin absorbency characteristic insofar as it will soak
up synthetic resin introduced into the interior of the tube 14 so
that the layers 28 and 36 become impregnated with said resin.
The inflation tube 16 in the embodiment illustrated is similar to
tube 14 insofar as it is provided with an outer membrane 40 which
is bonded to an inner felt layer 42 and this material is coiled
sewn and sealed in a similar fashion to material of the tube 14,
but there is no additional thinner layer 36 and the felt layer 42
is thinner than the layers 28 and 36. The tube 16 furthermore is
sized so as to be smaller than tube 14 because eventually it will
fit inside this tube. The tube 16 can however be of a single layer
material such as tube 12.
The inversion tube 22 as shown in FIG. 2 is simply a length of tube
similar to tube 12 (or it may be an extension of tube 16 or tube
14) connecting the ends of the tubes 14 and 16, but in addition
tube 22 is formed with a central tuck 44 for a purpose to be
explained. The length of the inversion tube 22 with the tuck 44 is
to D for a purpose to be explained in relation to the installation
procedure illustrated with reference to FIGS. 3-7.
In the embodiment described, the leading end of the tube 14 is
sealed as is the trailing end of the tube 16, and the inversion
tube 22 forms a seal between the trailing end of tube 14 and the
leading end of tube 16, but prior to sealing the leading end of
tube 14 and the trailing end of tube 16, a sufficient amount of
synthetic resin is introduced into the tubes 14 and 16 in order to
impregnate the felt layers 28, 36 and 42, and also to expel all air
from inside the tubes. In fact therefore these tubes 14 and 16 will
be in a flattened collapsed state, full of resin, but devoid of any
air therein.
If reference is now made to FIGS. 3-7, an explanation is given as
to how the tube assembly of FIG. 1 is inserted into an underground
sewer in order to create a lining for same.
In FIG. 3, the sewer is indicated by reference 50 and in fact is a
length of sewer extending between two manholes 52 and 54. The sewer
length 50 may require restoration or rehabilitation because of
deterioration as a result of usage and age, which is a common
problem with sewers of developed areas throughout the world.
It is also to be mentioned that in order to effect the lining
operation to be described appropriate equipment must be provided on
site such as pumps, vehicles, scaffolding etc., but such equipment
has been omitted from the drawings in the interests of simplicity
and also because the equipment for performing the methods is now
well known.
Into the manhole 52 is placed an elbow pipe 56 so that the open
lower end of the elbow 58 faces the end of the sewer 50 to be
lined. The leading end of the tube 12 is fed into the pipe 56, and
is folded back as shown so as to be connected to the lower end of
the elbow. Filling of the pipe 56 with water as indicated by arrow
60 in FIG. 4 causes the tube 12 to evert out of the end of the pipe
56 and into and along the sewer length 50 as shown clearly in FIG.
4. As the tube 12 everts so it pulls the next section of the tube
assembly namely the lining tube 14 into and along the sewer length
50 as shown in FIG. 4. FIG. 5 shows the position when the prelining
tube 12 has completed its eversion and the lining tube 14 is now in
the correct position with its respective ends at the ends of the
sewer section 50 to be lined. At this point the procedure is
stopped, and it will be noticed that the inversion tube 22 is now
located so that the leading half of same is in the pipe 56 and the
tuck 44 is adjacent the top end of the pipe 56.
At this juncture, the end of the prelining tube 12 adjacent the
manhole 54 is punctured in order to allow release of the water
which was used for the initial inversion step, as indicated by
arrow 62 in FIG. 6, and at the same time the tuck 44 in the
inversion tube is folded over the top edge of the pipe 56 also as
shown in FIG. 6 and is anchored thereto. The tuck can now be filled
with eversion fluid e.g. water as indicated by arrow 64 in FIG. 6,
which causes the second half of the inversion tube to evert into
the first half and down the pipe 56, at the same time forcing the
water from the puncture 62. To thus fold the tuck over the top of
pipe 56 it may be necessary to remove adhesive strips 66 as shown
in FIG. 2 which are applied across the tuck so that same will be
retained during the initial inversion step and other handling of
the tubular assembly.
With the continued supply of water 64 to cause the second half of
the inversion tube to evert into the pipe 56, so the last pipe
section 16 is pulled through pipe 56 and everts into the lining
tube 14 and inflates same as indicated in FIG. 7. Therefore, the
inner felt face 68 (FIG. 1C) of the lining tube 16 comes face to
face with the inner felt face 70 of the tube 16.
As these felt layers are impregnated with uncured synthetic resin,
so the felt layers of the respective tubes 14 and 16 in effect
coalesce into a single integrated resin mass as shown in FIGS. 8
and 9.
The resin subsequently is cured by any suitable means such as by
hot water or by light radiation, ultrasonics or other means and
when the resin cures hard, a rigid pipe lining the sewer length 50
results.
Instead of using a preliner tube 12, the main tube 14 may be pulled
directly into the passageway, especially when the passageway is
smooth, using for example a rope.
Many advantages flow from the various aspects of the present
invention which not only include the methods referred to herein,
but also include the tubular assembly.
These advantages include that by using a preliner tube and by
pulling the liner tube into the passageway using the preliner tube
and water, the liner tube can be supported by the water and will
slip easily into position. Secondly, as the liner tube does not
require to evert during any stage of the process, heavier liner
tubes can be installed and they will easily pass round bends and
corners.
The utilisation of an inflation tube which is integrally connected
to the lining tube ensures accuracy of positioning and accuracy of
inflation of the lining tube, and sealing of the ends of the tubes
means that all air can be excluded, which is highly desirable for
this process as the entrapment of air in the felt layers 28, 36 and
42 creates undesirable problems.
Although tubes which are impregnated with uncured synthetic resin
are described, it is to be mentioned that these tubes could be
constructed essentially of pre-preg materials of a type disclosed
in our co-pending Patent Application No. 8906467.9.
* * * * *